XDomainRequest: Microsoft unfortunately continues with XDomainRequest rather than making changes to XMLHttpRequest as other browsers are doing and as is being standardized by the W3C Web Apps Working Group. (Disclaimer: I am the editor of XMLHttpRequest Level 2.)

Some agreement was made to at least support the same protocol on the server, namely using the Access-Control-Allow-Origin header as per Access Control for Cross-Site Requests. (Disclaimer: I am the editor of that draft too.) However, IE8 only supports * as value for that header, not an origin, e.g. http://annevankesteren.nl (test). Sunava pointed out that was because the W3C WebApps WG was still debating the matter. Here is hoping they will fix the bug as there is agreement on that syntax.

HTML5 DOM Storage: localStorage and sessionStorage are now supported. Enumerating through them does not give the results I was expecting (I got “length” and “remainingSpace” back as well, besides the keys) and they still have a remainingSpace member that is not part of HTML5. Given that anything that gives some indication of space is highly vendor specific as it depends on encoding, compression, and type of device, they should really rename it to msRemainingSpace or some such or simply drop it.

IE8 also supports an event named storagecommit that is not part of HTML5 which tells you when the data has been written to an XML backend format IE8 uses. The event object for used for the storage does not expose key, oldValue, and newValue. The url member is named uri and the source member is null rather than a reference to the Window object. Ouch!

ARIA: Aaron Leventhal recently blogged about how ARIA in IE8 is a pain. (Aaron works for IBM making Firefox and Web applications accessible and is a member of the W3C PF WG which standardizes ARIA.) In short, when IE8 renders in super standards mode ARIA will work as everywhere else, otherwise you have to use Microsoft proprietary syntax. So not only do you need to upgrade your application code to be keyboard accessible and ARIA-enabled, you will also need to upgrade it from quirks to standards mode. Alternatively, you could take the easy way out and lock out other browsers. Not nice.

He did admit that he has “only played around with Internet Explorer 8 for an hour so” :)

@Douglas
I am not sure if this is you, though I guess so. This wasn’t really neither a mature thing to say…
Even I realize that probably both ActiveX, Silverlight, Adobe Flex, .wmf and so on are “better” than the Open Web thing. Just as we could probably find a better interface between lighbulbs and wall-connections or we could find a more optimal width for train tracks and such. No unless interoperability are a feature by itself we obviously have a holy duty in turning those things DOWN!
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This is especially true when some lock-in vendor creates “extensions” and “better versions” made to replace.
Some people could probably find features with IE’s Box Model and so on, that doesn’t make it BETTER…

@ThomasHansen: The old IE box model is better. When I set a div’s width, that ought to be it’s width god damn it. The idea that “width” means “the number of pixels from the leftmost pixel of text inside a shell of indeterminate dimensions to the theoretical rightmost pixel of text inside that shell” is ridiculous. There are obviously advantages and drawbacks to both, but the old IE box model wins hands down for allowing you to write code that does what it says, at least for code relevant to the box model.
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People, rightly, criticize Microsoft for creating conditions that require us to write massive divergencies for their browser. I think that criticism is also valid when directed at the W3C and the other browser vendors where the box model is concerned; I can’t count the thousands of lines of CSS I’ve written to work around the braindead standard.

@eyelidlessness
Wow, I didn’t know :)
I believe you too in fact…
Though standards are here to make sure that we can interop and have stuff that works on ALL browsers. To not at least implement the standards BEFORE you implement anything else is a crime against humanity…

This was a case, however, where the standard was wrong, or rather, more problematic to use and IE’s model already existed. It is also the job of standards bodies (especially non-official standards bodies like the W3C) to identify existing practice and specify to specify it to facilitate interoperability on the most coherent existing practice.

@eyelidlessness
I agree, and that job would probably be way easier if Microsoft cared about them and actually committed to them and worked with w3c instead of torpedoing them every occasion they get…
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Microsoft have deliberately put themselves on the outside of these [standard] bodies since they have historically found themselves in a position where it “makes sense” from a strategical and money-making perspective. Now they pay the price for their ignorance and selfishness…

“I agree, and that job would probably be way easier if Microsoft cared about them and actually committed to them and worked with w3c instead of torpedoing them every occasion they get…”
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You’re not… wrong. But it’s sort of a weird case to bring that up. With the box model, the standards bodies “torpedoed” existing practice and chose something more complicated and less intuitive. They didn’t *have* to do that, and certainly Microsoft didn’t force that.
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“Now they pay the price for their ignorance and selfishness…”
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How so?

@eye…
I am not sure if we should take this one that much further since it’s beginning to become pretty off topic, but the interesting thing is *not* their current market share, but how much they have *lost* the last three years…
(hint, they used to have 95% ;)

Shrug, no one is commenting on-topic so I’m not concerned about it.
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Yeah, they’ve lost market share. But considering the market has three (four if you count Chrome) obviously technologically superior browsers, all of which have together taken three years to take ~20% of IE’s share, I don’t think that’s a sign of widespread lack of trust, and it’s certainly not an instance of obscurity!

But that kind of a prediction is totally naïve. People aren’t automaton slaves to statistical trends; there is a reason so many have kept using IE, and not all of them are satisfied with other offerings. I have a friend, in fact, who I yell at whenever I have to fix some bug or another in IE, because he likes it.